Project 2 - Behavioral/Neuroscience

正常的衰老伴随着认知控制力的下降，这在一定程度上是由折衷的 前额叶皮质功能。然而，前额叶变化对其他皮质结构的影响 被招募来进行认知控制的人还没有被很好地理解。在这个项目中，听觉空间注意的控制将 用于研究前额叶和后叶皮质区域之间的相互作用，以及这些相互作用是如何 受年龄和任务要求的影响。我们的主要假设是，与年龄相关的认知变化 控制是由前额叶和顶叶/颞叶之间协调的网络水平损伤所介导的 肺叶区域。推论认为，衰老与受限的空间注意力梯度有关 (目标1)，以及空间定向对知觉和短期记忆负荷操作的更高敏感性 (目标2)，两者都可以通过磁刺激皮质来改善(目标3)。方法包括使用 脑电和事件相关电位确定前额叶和前额叶之间的皮质处理和相互作用 后方区域。空间梯度将通过呈现来自不同位置的声音虚拟现实刺激来映射 在任务执行期间在正面方位面上。经颅磁刺激将用于 暂时影响前额叶皮质活动。经颅磁刺激的效果将是 使用行为和脑电/事件相关电位测量进行评估。提出了三个具体目标。 在目标1中，将使用神经电测量来评估空间注意梯度的年龄差异 干扰刺激的自动(失配负向)和受控(P3a)加工。目标2将测试 一种假说，即认知控制能力的下降与感知能力的降低和认知能力的提高有关 短时记忆中的主动性干扰。单独的实验将在参数上改变知觉或 短期内存负载，并分别评估高和低主动干扰条件 内存负载实验。目标3将确定大脑皮质的磁刺激是否可以拓宽空间 注意梯度和提高认知控制任务的表现。

Normal aging is accompanied by declines in cognitive control that are mediated, in part, by compromised prefrontal cortex function. However the repercussions of prefrontal changes on other cortical structures recruited for cognitive control are not well understood. In this project control of auditory spatial attention will be used to study interactions between prefrontal and posterior cortical regions, and how these interactions are affected by age and task demands. Our overarching hypothesis is that age-related changes in cognitive control are mediated by network level impairments in coordination between prefrontal and parietal/temporal lobe areas. Corollary hypotheses are that aging is associated with constrained spatial attention gradients (Aim 1), and greater sensitivity of spatial orienting to perceptual and short-term memory load manipulations (Aim 2), both of which can be improved by magnetic stimulation of cortex (Aim 3). Methods include using EEG and event-related potentials to define cortical processing and interactions between prefrontal and posterior areas. Spatial gradients will be mapped by presenting acoustic virtual reality stimuli from locations in the frontal azimuth plane during task performance. Transcranial magnetic stimulation will be used to temporarily influence prefrontal cortical activity. The effects of transcranial magnetic stimulation will be assessed using behavioral and EEG/event-related potential measures. Three Specific Aims are proposed. In Aim 1 age differences in spatial attention gradients will be assessed using neuroelectric measures of automatic (mismatch negativity) and controlled (P3a) processing of distractor stimuli. Aim 2 will test the hypothesis that declines in cognitive control are associated with reduced perceptual capacity and greater proactive interference in short-term memory. Separate experiments will parametrically vary perceptual or short-term memory load, with a separate assessment of high vs. low proactive interference conditions in the memory load experiments. Aim 3 will determine if magnetic stimulation of cortex can broaden spatial attention gradients and improve performance on cognitive control tasks.